At certain frequencies, microwave energy can produce controlled ablation of biological tissue. For example, microwave energy having a frequency between 14 and 15 GHz has a relatively limited depth of penetration into biological tissue, which is beneficial for ablation control.
WO 2004/047659 and WO 2005/115235 disclose apparatus for and methods of both controllably ablating biological tissue and measuring information about tissue type and/or state using microwave radiation. These documents disclose the benefits of performing dynamic impedance matching between the energy source and the tissue.
WO 2008/044000 discloses a radiating scalpel suitable for use with the ablation apparatus mentioned above. The scalpel comprising an antenna arranged to emit a substantially uniform microwave radiation field along the cutting edge (i.e. blade) of the scalpel. The emitted microwave radiation is able to cauterise biological tissue during cutting, which facilitates invasive surgery performed on highly vascularised organs such as the liver.